Finishing lathe



Oct. 29, 1929. F. scHlMMEL FINISHING LATHE Filed April 6, 1927 y /JISLZ Patented Oct. 29, 1929 UNITED STATES FRIDOLIN SGHIMMEL, OF FARIBAULT, MINNESOTA FINISHING LATHE Application led. April 6,

My present invention has for its object to provide an extremely simple and highly efficient finishing lathe, and to this end it consists of the novel devices and combinations 0f devices hereinafter described and defined in the claims.

Said lathe, while intended for general use, is especially well adapted for sanding turned objects such as table legs and the like.

1n the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a view of the finishing lathe partly in central vertical section and partly in side elevation, with some parts broken away; and

F ig. 2 is a view partly in side elevation and partly in central section and showing another form of centering device for the headstock.

The numeral 3 indicates a frame having a bed 4 in which is formed a longitudinally extended slot 5. A headstock 6 is rigidly secured by screws to the bed 4 at the left-hand end of the slot 5. On the top of the headstock 6 is a horizontal sleeve bearing 7 in which is removably mounted a fixed tubular shaft 8 held in position by a set screw 9.

The hub 10 of a relatively large wheel 11 is journaled on the tubular shaft 8 and held against axial movement thereon by the bearing 7 and a collar 12 integrally formed with the inner end of said tubular shaft. A thrust bearing 13 is interposed between the bearing 7 and hub 10. rllhe wheel 11 is driven from an electric motor, not shown, by a belt 14 which runs in a groove formed in the periphery of said wheel.

A chuck 15, having a cylindrical body, is removably secured to the wheel 11 in axial alignment therewith by screw-threaded engagement with the inner end of the hub 10. Within the lchuck 15 is a cylindrical centering device 16 having a recess 1'?, said centering device being integrally formed with the inner end of a cylindrical plunger 18 mounted in the fixed shaft 8 for endwise movement and supporting the centering device 16 in axial alignment with said chuck. For yield- 50 ingly holding the plunger 18 inwardly pro- 1927. serial No. 181,413.

jected, there is provided a rocking weight 19 fulcrumed at 20 to the base of the headstock 6 and hingedly connected to said plunger by a headed stud 21 having screw-threaded engagement with said weight and extending loosely through a bore formed in the flattened outer end portion of the plunger 18.

Normally the weight 19 rests on an adjustable abutment 22 in the form of a headed screw having threaded engagement with a nut-acting sleeve mounted in the bed 4. lVhen the weight 19 is resting on the abutment 22 it holds the plunger 18 with the centering device 16 projected axially outward of the chuck 15. By adjusting the abutment 22, the centering device 16 may be positioned in different adjustments With respect to the chuck 15. The weight 19 works in a passageway 23 formed in the headsto-ck 6.

A tailstock 24 is mounted on the bed 4 and provided with a pair of depending screwthreaded studs 25 which project through the slot 5 and have washer-equipped thumb nuts 26 by which the tailstock 24 may be clamped onto the bed 4 in different adjustments with respect to the headstock 6. On the top of the tailstock 24 is a sleeve bearing 27 in which is a plunger 28 mounted for axial movement. A centering device 29 is mounted in the borelike recess in the inner end of the plunger 28 and provided with a conical point axially aligned with the centering device 16. The centering device 29 is held against removal from the plunger 28 but with freedom for rotation by a screw 30 which extends into an annular channel 31 formed in said device. A thrust ball 32 is interposed between the inner end of the centering device 29 in the bottom of the recess formed in the plunger 28.

Axial movement is imparted to the plunger 28 by a hand lever fuicrumed at 34 to the bed of the tailstock 24 and intermediately connected at 35 to the outer projecting end of said plunger. An arm 36 is integrally formed with the lever 33 in bell crank arrangement and projects through a passageway 37 in the tailstock 24. Suspended from the arm 36 by an eye bolt 38 is a weight 39. Obviously, this weight 39 holds the centering device 29 projected toward the centering device 16.

Mounted in the lathe is a turned table leg a; to be sanded. In the upper end of the table leg a, at the axis thereof, is a wood screw ZJ for the purpose of attaching said legI to the table top. As previously stated, the centering device 16 projects outward of the chuck 15. To mount the leg a in the lathe, the lever 33 is first thrown outward to retract the centering device 29 against the action of the weight 39.

While the opera-tor is thus holding the lever B3 with one hand, he picks up the leg a and inserts the screw Z) into the recessed centering device 16. rlhe chuck 15 at this time is of course being rotated by the motor. The operator then positions the point of the centering device 29 in alignment with the center point formed in the lower end of the leg a at the time the same was turned. 1While the leg a is thus held, the operator allows the lever 33 to be moved inward under the action of the weight 39 and thereby causes the point of the centering device 29 to enter the center point in the lower end of the leg a. `With the leg a thus supported by the centering devices 16 and 29, the operato-r releases the lever 33 and the weight 39, which has a greater eii'ect than the weight 19, moves the leg a toward the headstock 6, and thereby retracts the centering device 16 bylifting the weight 19 and allowing the upper end ot' the leg a ltbc engage the chuck 15 and be rotated there- The centering device L10 shown in Fig. 2 is provided with a conical point, and is provided as a substitute for the centering de.- vice 16 when the object to be mounted in the lathe is not provided with a screw or other attaching devices.

From the above description it is evident that objects may be mounted in the lathe and removed therefrom without stopping the rotation of the chuck 15.

What I claim is:

1. A lathe having a chuck provided with a relatively axially movable centering device, a yielding pressure device exerting a pressure on the centering device to projecty the same o-utward of the chuck, said pressure device having a decreasing pressure on the centering device as the same is moved into the chuck by the work, and a tailstock having a centering device exerting sutlicient pressure on a piece of work held by the centering devices to overcome the pressure device for the centering device of the chuck and move said work into engagement with the chuck.

2. A lathe having a chuck provided with a relatively axially movable centering device, a fulcrumed weightV exerting a pressure on the centering device to project the same outward of the chuck, the ulcrum for said weight being arranged to cause the weight to decrease its pressure on the centering device as the same is moved into the chuck by the work, and a tailstock having a centering device exerting sufficient pressure on a piece of work held by the centering devices to overcome thepressure device for the centering device of the chuck and move said work into engagement with the chuck.

3. vA lathe having a chuck and a tail stock each of which is provided with a relatively axially movable centering device, two 0pposingyielding pressure devices for the centering devices and operative to project the same toward each other, the pressure device for the centering device of the tail stock eX- erting sufficient force on a piece of work held by the centering devices to overcome the pressure device for the centering device of the chuck and move said work into engagement with the chuck. v

4. The structure defined in claim 3 in which the pressure device for the centering 

